Expose BootBuildImage's cleanCache property as a command-line option

See gh-23753

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -129,7 +129,7 @@ Acceptable values are `ALWAYS`, `NEVER`, and `IF_NOT_PRESENT`.
 |
 
 | `cleanCache`
-|
+| `--cleanCache`
 | Whether to clean the cache before building.
 | `false`
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImage.java

@@ -214,6 +214,7 @@ public class BootBuildImage extends DefaultTask {
 	 * Sets whether caches should be cleaned before packaging.
 	 * @param cleanCache {@code true} to clean the cache, otherwise {@code false}.
 	 */
+	@Option(option = "cleanCache", description = "Clean caches before packaging")
 	public void setCleanCache(boolean cleanCache) {
 		this.cleanCache = cleanCache;
 	}